2022 POLAR BEAR RESEARCH MASTERPLAN - Polar Bear Research Council Association of Zoos and Aquariums Polar Bear Species Survival Plan - Cincinnati ...
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2022 POLAR BEAR
RESEARCH MASTERPLAN
Polar Bear Research Council
Association of Zoos and Aquariums
Polar Bear Species Survival Plan
This publication may be cited as:
Polar Bear Research Council. 2022. 2022 Polar Bear Research Masterplan.
Polar Bear Species Survival Program, Association of Zoos and Aquariums.
On the cover: Polar bear Tasul swims into an underwater swim flume as part of a collaborative
metabolic study at the Oregon Zoo. Photo by Michael Durham/Oregon Zoo.
Table of Contents
AZA Polar Bear SSP Research Council . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
List of PBRC endorsed, ongoing research projects as of June 2021 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Field Techniques . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8
Health and Welfare . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
Physiological and Behavioral Ecology . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Reproduction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Dr. Anthony Pagano records behavior exhibited by Oregon Zoo polar bear Tasul, voluntarily sporting a research collar
fitted with an accelerometer device. Photo by Michael Durham/Oregon Zoo.
O
ver the past 40+ years, scientists have overcome
tremendous logistical challenges to study wild
polar bears, and I feel fortunate for the role I’ve
played in that progress. Prior to joining Polar Bears
International as chief scientist in 2010, I led polar
bear research in Alaska for 30 years. My three decades of in situ
fieldwork helped provide essential information on polar bear
movements, distribution, population trends, life history traits,
and basic biological needs—knowledge that has added greatly
to our understanding of the bears and the actions needed to
ensure their future.
This research culminated in the projection that, without action
on human-caused climate warming, polar bears could all but
disappear by the end of the century. As a result, polar bears
became the first species listed under the U.S. Endangered
Species Act due to the threat of global warming.
Dr. Steven C. Amstrup Continuing in situ research on wild polar bears across the Arctic
has confirmed the threat of climate warming and provided the mechanistic underpinnings of polar bear
life history needs. It also has shown that some vital studies simply cannot be conducted in the wild.
This is where zoos and aquariums can play a critical role. Bears in managed care can be repeatedly
observed and sampled over long time periods—allowing sample size and replication not possible in the
field. Such studies can fill critical knowledge gaps while testing and calibrating new research methods
and technologies before they are deployed in the field.
Through projects supported by the Polar Bear Research Council, of the Association of Zoos and
Aquariums, AZA member institutions have partnered with universities, government agencies, and Polar
Bears International on research ranging from determining the polar bear’s energy use when walking,
running, and swimming to testing new devices for following the movements of bears in the wild. Ex
situ research in zoo settings combined with in situ field research showed how polar bears use scent
communication as they search for mates on broad expanses of pack ice. And studying polar bear hair
and tissue samples from zoo animals have helped us understand wild bear diets.
The Polar Bear Research Masterplan is a living document that prioritizes ex situ research vital to polar
bear conservation and management. It serves as a roadmap to the roles zoos and aquariums can fill
in our understanding of polar bear life history needs. Presentation of ex situ research also can capture
public attention and enhance the opportunities for zoos and aquariums to educate the public about the
threats polar bears face—inspiring actions necessary to preserve them in the wild.
The combination of ex situ research opportunity with potential for outreach and education means zoos
and aquariums can play a vital role in helping to assure future survival of polar bears throughout the
Arctic. This document is a valuable resource for guiding, facilitating, and supporting this important work.
Sincerely,
Dr. Steven C. Amstrup
Chief Scientist, Polar Bears International
4 | PRBC Masterplan 2022
Mission: To ensure a robust, thriving zoo population The Polar Bear Research Council (PBRC)
of polar bears is involved in research that produces
solutions to conservation and management challenges
facing wild bears.
T he PBRC is composed of a Steering Committee that
includes two PBRC Co-Chairs, the PBRC Facilitator
and the Polar Bear SSP Chair. Additional members
Description: The Polar Bear SSP’s designation as a include advisors with expertise/experience in four
research population signals a shift toward requiring priority research areas (see below). Priority research
member participation in priority research projects advisors are responsible for recruiting input from
with polar bears ex situ that can inform critical additional experts (typically 3-6) who can provide
conservation and management questions that exist thoughtful reviews and unique perspectives to ensure
for polar bears in situ. For a research program to be the PBRC Masterplan is accomplished.
successful, a diverse population of animals must be The PBRC’s goals are to: 1) facilitate the use of the ex situ
maintained, individual animal welfare must factor population to better characterize basic biology and to
into decision-making and AZA facilities must work to advance scientific methodologies for comparison and
ensure that viable candidates are available for research. application to wild polar bears; 2) support research that
Additionally, AZA facilities must ensure that staff are is necessary for maintaining a viable, sustainable ex
trained in sample collection and training techniques, situ population for scientific research with application
and that facilities are designed to accommodate to the conservation of wild bears; and 3) build capacity
sample collection and/or research. Future polar bear within SSP member institutions to participate in priority
SSP master-planning will center around maximizing scientific research efforts.
our participation in meaningful conservation science.
Rationale: Polar bears in managed care can Purpose of the PBRC and the Research Masterplan
T
participate in valuable research that helps to conserve he purpose of the Polar Bear SSP Research
and understand polar bears in the wild. Zoo- and Masterplan document is to: 1) guide research
aquarium-housed polar bears can be trained via priorities for the Polar Bear SSP and participating
operant conditioning to voluntarily participate in institutions, 2) advise the Polar Bear SSP on proposal
hands-on procedures and longitudinal biological endorsement requests, 3) facilitate priority research
sampling. These bears have the added advantage in efforts in SSP institutions, 4) keep current with
that their husbandry histories and medical records are emerging scientific questions regarding survival of
available, environmental conditions are known and can polar bears in the wild, and 5) track progress made
be adjusted, and monitoring can be continuous during through the collaborative scientific studies of polar
a study. Through multi-institutional collaborations, bears in managed care and of contributions made
scientists can recruit a larger sample size of polar by zoos and aquaria to wild polar bear research. The
bears that ensure sufficient statistical power in masterplan is a living document that is intended to
studies on behavior, physiology, health, reproduction, be updated every three to five years. This current
and welfare. Polar bears in managed care can also masterplan is the 1st revised version of the original
contribute to the development and validation of new masterplan published in 2018.
technologies and methodologies for use with wild
bears, the true beneficiaries of this initiative. Photo © Daniel J. Cox/NaturalExposures.com
PRBC Masterplan 2022 | 5
AZA Polar Bear SSP Research Council
Co-Chairs Priority research pillars and
corresponding advisors
Dr. Terri Roth, Center for Conservation and Research
of Endangered Wildlife (CREW), Cincinnati I. Field Techniques Advisors
Zoo & Botanical Garden; email: terri.roth@
cincinnatizoo.org Dr. Thea Bechshoft, Polar Bears International;
email: thea@pbears.org
Dr. Megan Owen, San Diego Zoo Wildlife Alliance;
email: mowen@sdzwa.org Dr. Stephen Petersen, Assiniboine Park Zoo;
email: spetersen@assiniboinepark.ca
Facilitator and Contact: Amy Cutting, Oregon Zoo; II. Health and Welfare Advisor
email (preferred) Amy.Cutting@oregonzoo.org;
Dr. Randi Meyerson; email: randimeyerson61@
cell: 503-757-8163; Office: 503-220-2446
gmail.com
AZA Liaison: Steve Olson, Senior Vice President,
Government Affairs, Association of Zoos and III. Physiological and Behavioral Ecology Advisors
Aquariums (AZA); email: solson@aza.org
Dr. Karyn Rode, United States Geological Survey
Polar Bear SSP Chair: Allison Jungheim, Como Park (USGS); email: krode@usgs.gov
Zoo and Conservatory; email: allison.jungheim@
Dr. Anthony Pagano, Washington State
ci.stpaul.mn.us
University; email: ampagano@ucsc.edu
IV. Reproductive Physiology Advisor
Dr. Erin Curry, CREW, Cincinnati Zoo & Botanical
Garden; email: erin.curry@cincinnatizoo.org
6 | PRBC Masterplan 2022
List of PBRC endorsed, ongoing research projects
as of June 2021
Project title PI and affiliation
1 Macronutrient requirements and intake of Karyn Rode; USGS; krode@usgs.gov
polar bears
2 Comparative analyses of the Shannon Atkinson and Monica Brandhuber;
expression of reproductive steroids and University Fairbanks; shannon.atkinson@
dehydroepiandrosterone sulfate (DHEAS) in alaska.edu
captive and wild female polar bears.
3 Characterization of the gut microbiota in Peko Tsuji and Maci Quintanilla; Towson
polar bears and a metabolic analysis University, MD; ptsuji@towson.edu
4 Development of dynamic energy budget Stephanie Penk; University of Toronto;
models in complex vertebrate mammals sr.penk@mail.utoronto.ca
to understand past and future population
dynamics.
5 Validation and characterization of Erin Curry, Jessye Wojtusik, Terri Roth;
reproductive hormones and biomarkers Cincinnati Zoo/CREW; erin.curry@
in polar bear serum cincinnatizoo.org
6 Analyzing hormone patterns of captive Dylan McCart, Suzanne MacDonald; York
male polar bears housed under different University; dylanmccart@hotmail.com
social conditions
7 Assessing the timing and rate of fur Jennifer Stern, University of Washington
growth in zoo polar bears and Karyn Rode, USGS; jhstern@uw.edu
8 Polar bear ear measurements (for new Elisabeth Kruger; World Wildlife Fund;
ear tag tracking device) Elisabeth.Kruger@wwfus.org
9 Serum concentration comparisons of fatty Deb Schmidt, St. Louis Zoo and Karyn Rode,
acids, amino acids, vitamins, minerals, and USGS; schmidt@stlzoo.org
cholesterol, between free-ranging and zoo
polar bears
10 New attachment techniques for electronics Geoff York, Polar Bears International;
to polar bears – Project “Burr on Fur” gyork@pbears.org
PRBC Masterplan 2022 | 7
FIELD TECHNIQUES
Field Techniques
(In-field monitoring and management techniques)
Advisors: Dr. Thea Bechshoft, Polar Bears
International
Dr. Stephen Petersen, Assiniboine
Park Zoo
Experts: BJ Kirschhoffer, Polar Bears International
Liz Larson, Utah’s Hogle Zoo
Alysa McCall, Polar Bears International
Dr. Nicholas Pilfold, San Diego Zoo
Wildlife Alliance
Dr. Tom Smith, Brigham Young University
Geoff York, Polar Bears International
Explanation of the research focus area in
relation to polar bear conservation
The polar bear (Ursus maritimus) poses challenges for
researchers and conservationists in that it is a large top
predator that lives a primarily solitary life across vast
expanses in a harsh and remote environment. Polar
bear habitat also presents logistical difficulties and
safety concerns for researchers as it consists of sea ice,
marine waters, and terrestrial areas that experience
a wide range of often unforgiving environmental Photo © Daniel J. Cox/NaturalExposures.com
conditions. When polar bears do occur near humans
and their infrastructure successfully co-existing can
will provide the desired data and results. An additional
present a significant risk and challenge. Together,
benefit is that the newly developed methods are often
these factors often hinder effective research and
less invasive than the more traditional approaches to
conservation efforts of polar bears across the Arctic. polar bear research.
Technical and technological advances can play a
vital role in overcoming this challenge, particularly The Field Techniques advisory group includes projects
those that have been developed in collaboration with with direct in-field applications, in particular studies
institutions that have polar bears in their care. These that test equipment for field deployment or validate
bears can participate in scientific studies in a controlled new (or new applications of already existing) methods
environment, with subjects that can be repeatedly and technologies that directly inform in situ polar bear
observed, monitored, or examined. Thus, applied research and conservation. Meanwhile, projects focused
monitoring and conservation tools that have been on advances in laboratory analyses and techniques
developed using ex situ bears can be nearly field-ready will sort under either the Physiological and Behavioral
before being deployed in situ, reducing the chance of Ecology, the Reproductive Physiology, or the Health and
failure, and increasing the chances that field results Welfare advisory groups as deemed appropriate.
8 | PRBC Masterplan 2022
FIELD TECHNIQUES
Recent examples of published work that
has happened in zoo settings and how it has
complemented or informed our understanding of
polar bear biology and management
Identifying bear behavior from activity sensors
Pagano et al. (2017) and Ware et al. (2016) used
activity sensor data on collars of zoo bears to relate
collar activity to individual bear behaviors. Those
relationships have then been used to be able to
identify the behaviors of wild bears our on the sea ice
based on historic and contemporary activity sensor
data thereby better understanding the behavior of
bears when and where they can rarely be observed.
Energetic costs of locomotion in bears Infrared thermography image of a male polar bear.
Pagano et al. (2018a) - Polar bears in human care were Image by Dylan McCart and Dr. Michelle Shero.
trained to voluntarily walk on a treadmill in a special
chamber that could analyze the breath of the bear. their blood and hair. Using this information, correction
This allowed scientists to record how the bear was factors were identified that allow estimation of the
moving at as well as the amount of energy they were prey species and macronutrient composition of wild
expending. This information was then used to predict polar bear diets from these same tissues. Further, this
energy use in wild bears. study determined the timeframe of diet represented in
these tissues to improve interpretation of wild samples.
Identification of individual bears
Prop et al. (2020) - Sets of photographs of 15 polar Priority areas that should take precedence
bears from six AZA and EAZA zoos were used to within this research pillar
develop a new method for individual recognition,
Given the unpredictable nature of methodological
based on distinguishing a set of physiognomic
and technological advances, we have identified
characteristics, which can be recognized from
priority areas where new field techniques are likely
photographs taken in the field at distances of up to
400 m. Requiring less specific photos than the whisker to contribute significantly to our understanding and
spot recognition method (Anderson et al. 2010), conservation of polar bears.
this new method offers an additional method for 1. Population assessment: The key to managing
identification of individual polar bears in the wild. populations is obtaining regular and timely
population estimates to determine abundance and
Validating thermal imagery tools trends. For polar bears, this has been accomplished
Bissonette (2020) - Polar bears in human care were using capture-mark-recapture (hands-on and
filmed using an infrared camera while the bears sparred genetic) and via aerial surveys. All current methods
and played with each other. The change in the bear’s are expensive, high risk, and time-consuming
temperature signal from beginning of the play session and therefore cannot be done with the regularity
to the end of a session is related to the amount of needed for a species in a changing habitat such as
energy the bear has spent on that activity. Thermal the Arctic. Examples of emerging technology likely
imagery has been used to detect polar bear dens (Smith to assist in counting polar bears include remote
et al. 2020) but may also have other applications to help sensing tools that could help us accurately count
understand polar bear biology and behaviour. bears using drones, aircraft, or satellites (e.g., LaRue
et al. 2015, Barnas et al. 2018).
Improving diet estimates of wild polar bears
inferred from hair and blood samples 2. Movement and dispersal: Habitat use and
Rode et al. (2016) worked with zoos to feed polar requirements, movement, and dispersal studies
bears specific marine-based diets to trace how stable all rely on the tracking of individual polar bears.
isotopes of carbon and nitrogen in food is reflected in This has been done primarily using satellite-
PRBC Masterplan 2022 | 9
FIELD TECHNIQUES
GPS ear tag on a
tranquilized subadult
polar bear. Photo by Dr.
Andrew E. Derocher/
University of Alberta.
onshore and as human
activities in the Arctic
increase, both in response
to longer ice-free seasons
(Wilder et al. 2017).
To mitigate this, more
information is needed
on polar bear olfaction
and vision in relation to
potential deterrent tools
and methods. Further,
development and testing
of early polar bear
detection systems as well
as non-harmful deterrent
tools such as strobe
linked GPS collars, but there is an increasing lighting and specific sounds to examine their
need for redesign of these instruments to be efficacy in potential use as a deterrent option.
smaller, lighter, and more efficient. There is also
a need for them to be able to carry new sensors 5. Polar bear awareness: Human perceptions of polar
or be attached in different ways. Examples of bears and their actions can significantly influence
emerging technology likely to assist in tracking chances of human/bear conflict when working,
polar bears include miniaturization and new living, or recreating in the north. Social science
battery technology as well as new tracking device research that probes this relationship and explores
attachment strategies like the one used in the 3M ways to minimize conflict is needed.
Burr on Fur adhesive tags. A prototype of one of the Burr on Fur adhesive GPS tags.
3. Minimally invasive monitoring: Devices like As with the ear tags, these smaller tags allow us to study
camera traps, Doppler tracking radar, hair snags, not just adult females, but also males and younger
photogrammetric or laser-based body condition bears, collecting valuable information on the habitat
measures, and opportunistic collection of fecal use of these little-studied groups. Photo by 3M and Polar
samples are good examples of non-invasive Bears International.
monitoring tools. Approaches like these can
provide useful information on polar bears with
minimal disturbance or effect on the animal.
Non- or minimally invasive techniques should be
pursued and used whenever possible over invasive
techniques and can be tested and validated in
zoological or aquarium settings.
4. Polar bear/human coexistence: Sea ice loss
has led to an increase in polar bear sightings in
northern coastal communities around the Arctic,
a trend that is expected to continue as more polar
bears are forced to spend longer periods of time
10 | PRBC Masterplan 2022FIELD TECHNIQUES
Work currently underway or not yet published o Body condition; developing an algorithm
that allows body condition to be inferred
1. Population assessment from photographs or laser-based three-
dimensional imagery.
o Collection of aerial thermal images of polar
bears to train machine learning algorithms to o Individual recognition; further development
detect polar bears in seal surveys. of the automated system developed by the
Waterman group (Anderson et al. 2010) that
2. Movement and dispersal uses whisker spot patterns to identify bears.
o Testing of adhesive satellite tags that attach to
4. Polar bear/human coexistence
the bear’s fur while providing movement data.
o Ear tag redesign for a smaller more ergonomic o Early warning polar bear detection; developing
tag to replace the current bulkier design. a radar technology based system to reduce
human-polar bear conflict in remote locations.
3. Minimally invasive monitoring o Polar bear olfactory preferences; assessing a
range of scents for their properties as potential
o SAR (synthetic aperture radar); a device used attractants/deterrents.
to detect polar bear maternity dens under the
snow while flying overhead.
5. Improving methods for studying polar bear
o Maternal den studies; monitoring polar bear ecology from tissue samples
dens with remote camera systems to record
data on the activity of emerging polar bear o Assessing the timing and rate of fur growth
moms and cubs. in zoo polar bears to improve interpretation
of studies of diet, contaminants, and stress
hormones in fur.
Polar bear Nora swims in a metabolic chamber as part of an energetics study at the Oregon Zoo.
Photo by Michael Durham/Oregon Zoo.
PRBC Masterplan 2022 | 11HEALTH AND WELFARE
Health and Welfare
Advisor: Dr. Randi Meyerson
Experts: Dr. Dalen Agnew, Michigan State
University
Dr. Todd Atwood, USGS
Dr. Jonathon Cracknell, European
Association of Zoos and Aquaria
Dr. Wynona Shellabarger, Detroit
Zoological Society
Dr. Patricia Pesavento, University of
California, Davis
Explanation of the research focus area in
relation to polar bear conservation
The Veterinary Medicine Research subcommittee
identified health and welfare concerns of wild and
zoo managed polar bears, trends in pathology, and
the threat of emerging diseases in a warming Arctic
as their top priorities. Though the greatest threat to
polar bears is loss of sea ice, disease related factors
were identified as important criteria both for their 2008
listing under the Endangered Species Act (USFWS,
2008) and for recovery in the 2016 USFWS Polar Bear
Conservation Management Plan (USFWS, 2016).
Photo © Daniel J. Cox/NaturalExposures.com
A warming and changing Arctic environment is having
significant effects on wild polar bears. Shorter annual While types of impact, such as starvation, decreased
periods of sea ice availability, with corresponding reproduction and immune function, and increased
shorter periods of time for bears to hunt ice seals, susceptibility to disease are easy to predict; studies
has been associated with declines in body condition, of the S. Beaufort Sea polar bears demonstrate that
reproductive success, survival, and abundance. the specific effects on the differing subpopulations
Poor body condition decreases immune function, are not. Differing lengths of time on shore, types and
making the bears more susceptible to pathogens, levels of food source availability, and prior exposure
as well as the effects of fat-soluble contaminants, to pathogens were all shown to have significant effect
as their fat supplies become depleted. Additionally, on the health status of individual bears (Atwood et.al
a warming environment, with a greater ice-free 2017; Neuman-Lee et. al 2017).
period, increases exposure to infectious diseases,
both through increased concentration of conspecifics While a major focus of the polar bear research
and other species affiliated with human settlements, masterplan is to facilitate ex situ research to help
as well as northern migration of novel pathogens answer in situ questions, the plan also prioritizes the
and vectors (Fagre et al., 2015). As the loss of sea ice need to continue addressing the health and welfare
continues unabated, greater exposure to pathogens concerns of the zoo managed polar bear population.
and parasites has the potential to adversely affect the
health of the polar bear populations.
12 | PRBC Masterplan 2022HEALTH AND WELFARE
Male polar bear anesthetized for physical examination. Photo by Louisville Zoo.
Examples of work that has happened in zoo Pathogenic studies
settings and how it has complemented or informed Bears in our care, with known health histories,
exposure locations and the ability to provide
our understanding of polar bear biology and sequential blood samples can provide information
management related to pathogenic titers (Neuman-Lee et al.,
2017; Dutton et al., 2009). Study results have shined
Gene transcription studies a light on the large number of factors that must be
Studies of gene transcription have been conducted considered in interpreting results.
to assess ecological and anthropological stressors
(Bowen et.al, 2015). Results revealed immune function
impairment in polar bears from the Beaufort Sea, when
Research Priority Areas
compared with Chukchi and captive polar bears. Given the expanse of the study of polar bear health,
many of the issues identified in this section of the
Feeding trials document will also be included in other areas of the
Polar Bear Research Masterplan.
Studies involving closely monitored feeding trials
have been performed to quantify dietary lipid and Additionally, this section not only looks at veterinary
protein preference in zoo bears, and data have been issues involving wild polar bears, but the health and
compared with that from studies of wild bear diets to welfare of bears in human care as well. It is essential
infer optimal macronutrient intake (Rode et al., 2021). that zoo bears are healthy both mentally and physically
Results indicate that bears should consume more lipid and display many natural behaviors so that research
and less protein than previously thought. results are transferable to wild bears.
PRBC Masterplan 2022 | 13HEALTH AND WELFARE
1. Veterinary health and welfare: Although zoos o Investigate the polar bears’ ability to adapt to
have greatly improved their facilities and care higher thermal temperatures.
of bears over the years, managed polar bears
continue to face several challenges that may have o Identify and address behavioral and
an impact on their welfare. The success of the physiological causative and indicators of stress.
managed population depends on each individual
bear’s ability to thrive. Therefore, identifying factors 2. Pathology
in the physical and social environments that o Establish/centralize tissue and plasma banks in
contribute to positive welfare is critical. In addition US and Canada
to being an important conservation education
ambassador for climate change, these bears, as o Establish consistent necropsy protocols
participants in conservation relevant research, for field and zoo use which facilitate
afford the opportunity to better understand how collaborations and comparisons between
current and future environmental changes and zoo managed and wild polar bears. Including
challenges are affecting or will affect their wild “how to” photographic documentation,
populations as well. Whereas, some areas of study morphometrics, and the creation of a
are specific to their wild or captive status, other brief instructional video for necropsy
studies have relevance to both populations. procedures for field biologists.
o Investigate poor captive reproductive success. o Coordinate retrospective and prospective
necropsy data.
o Develop effective hand-rearing protocols.
o Standardize sampling techniques in the field
o Define effective care and management for and zoos in relation to histology, cytology,
geriatric bears. virology, toxicology, parasitology, biotoxins,
o Identify common dermatological issues and and genetics studies.
possible relationships to nutritional status,
immune function, reproductive status, and/or
water quality.
Voluntary blood collection from a polar bear. Photo by Como Park Zoo & Conservatory.
14 | PRBC Masterplan 2022HEALTH AND WELFARE
o Establish baseline assessment of infectious
disease burden.
o Establish baseline characterizations of the
microbiome and virome.
4. Technological Advancements for Healthcare
o Establish a protocol for indicators/measures
of stress- i.e. voluntary blood draw sampling
of consecutive cortisol levels after periods
of stress to help determine delay period
between stressor and blood/fecal/hair
cortisol level changes.
o Development of techniques that permit oiled/
ill/injured bears to be treated in situ and/or in
close proximity to their natural territory and
associated sub-populations.
o Optimize techniques and training of polar
bears for minimally invasive sampling and
veterinary treatments.
Studies currently underway or not yet published
1. Evaluation and comparison of Toxoplasmosis
gondii titers in wild and zoo polar bears and
Polar bear cub CT scan as part of neurological exam. implications to the health of the polar bears
Photo by Wynona Shellabarger/Detroit Zoological Society. and the Inupiat communities that harvest
them. R. Meyerson and W. Shellabarger, Detroit
Zoological Society.
3. Emerging diseases
2. Investigating the relationship between ambient
o Evaluate potential emerging diseases from conditions and thermoregulatory responses
vector migration northward as habitat warms- in polar bears. L. Graham, WRG Conservation
i.e. mosquitoes and West Nile Virus Foundation and Ryerson University.
o Evaluate disease concerns in their prey species; 3. Multi-institutional evaluation of peri-vulvar
both availability and possible cross-species dermatitis in female polar bears and implications
transmission. to welfare and health concerns in both zoo and
wild bears. E. Curry, Center for Conservation and
o Evaluate increased exposure at the human Research of Endangered Wildlife, W. Shellabarger,
interface to infectious disease carriers, such as Detroit Zoological Society.
domestic dogs and cats, as polar bears seek
out human food caches, and humans move 4. West Nile titers in zoo polar bears as indicators
into or spend greater amounts of time in more of threat to wild polar bears in a warming
northern latitudes Arctic. R. Meyerson and W. Shellabarger, Detroit
Zoological Society.
o Evaluate increased exposure to novel species
as a sequela to warming (isolation, migration)
or translocation (zoos)
PRBC Masterplan 2022 | 15PHYSIOLOGICAL AND BEHAVIORAL ECOLOGY
Physiological and Behavioral Ecology
Advisors: Dr. Karyn Rode, USGS
Dr. Anthony Pagano, Washington
State University
Experts: Dr. Thea Bechshoft, Polar Bears
International
Dr. John Whiteman, Old Dominion
University
Dr. Tom Smith, Brigham Young
University
Explanation of the research focus area in
relation to polar bear conservation
Understanding the mechanisms by which the current
and near-future status of polar bears will be affected by
sea ice loss and other ecosystem changes associated
with climate change is important for informing
management decisions and improving the accuracy
of long-term projections. Although information on Photo © Daniel J. Cox/NaturalExposures.com
population abundance and trends are critical, for
most polar bear populations the logistical limitations
of gathering data from a species that occupies a very Examples of work that has happened in zoo
large home range throughout remote regions of the settings and how it has complemented or
Arctic precludes estimation of population parameters. informed our understanding of polar bear
Thus, management decisions often must be made
based on inference of population dynamics based biology and management
on bear health, nutritional condition, behavior, and In recent years, a number of studies of polar bear
ecology. Further, as sea ice loss has become the physiological and behavioral ecology have been
primary threat facing polar bears, there is an increased conducted in zoos, with findings being applied to better
need to understand mechanistic relationships understanding polar bears in the wild. These include:
between sea ice loss and polar bear population
dynamics to improve short-term and long-term Validation of activity sensors
projections. Thus, increasingly polar bear studies have Validation of activity sensors in collars for identifying
focused on understanding behavioral responses to sea polar bear behavior including differentiating
ice loss and physiological limitations in their ability to resting versus active behavior from archived polar
adapt. To accommodate those studies, new methods bear activity sensor data (Ware et al. 2015; 2017)
are needed. Polar bears in zoos provide an excellent and classifying swimming, walking, and resting
opportunity for development of new methods to behavior using more recently developed tri-axial
monitor polar bear behavior and physiology in the wild accelerometers (Pagano et al. 2017).
and to better understand the physiological limitations
of the species. Quantifying stable isotopes
Quantifying routing of stable isotopes in polar bear
diets into tissues to use samples of polar bear blood and
hair from wild polar bears to estimate diets (Rode et al.
16 | PRBC Masterplan 2022PHYSIOLOGICAL AND BEHAVIORAL ECOLOGY
2016). This information will allow detection of dietary Chemical communication
changes over time that may be associated with sea Studying polar bear chemical communication to better
ice loss or other environmental changes. Because diet understand social behavior, including breeding (Owen
can affect exposure to contaminants and pathogens et al. 2015). Little has been known about how polar
(McKinney et al. 2009, 2017), dietary change is an bears communicate and maintain social relationships
important component of understanding potential out on the sea ice. Habitat fragmentation associated
cumulative effects of ecological change. with sea ice has been identified as a potential factor
that could disrupt breeding behavior in the spring. This
Measuring metabolic rates study provided baseline information needed in better
Measuring metabolic rates of polar bears while understanding potential implications of changing
walking and swimming (Pagano et al. 2018 b, c). habitat conditions on social interactions.
This information is important to understanding the
energetic costs of behavioral changes and variation Hearing sensitivity in polar bears
in polar bears. For example, polar bears have been Concerns regarding the spatial and temporal overlap
documented to increasingly swim long distances in of oil and gas activities and maternal denning on
the southern Beaufort Sea during the annual sea ice Alaska’s North Slope led to initiation of a studying
minimum (Pagano et al. 2012). Additionally, changes of hearing sensitivity in polar bears. These baseline
in patterns of sea ice drift have been shown to increase data (Owen & Bowles 2011) can be used to develop
the rate of walking polar bears must maintain to travel biologically relevant protective guidelines for
(Durner et al. 2017). Data on metabolic rates will allow industrial/human activity in sensitive polar bear
quantification of the impacts of such changes. habitat (Owen et al. 2021)
Female polar bear Tatqiq swimming in her pool at the San Diego Zoo while participating in a study designed
to validate collar-mounted activity sensor data. This study, co-led by USGS and the UCSC, contributed to the
behavioral classification of data generated by both tri-axial accelerometers and mercury tip-switch sensors.
Photo by San Diego Wildlife Alliance.
PRBC Masterplan 2022 | 17PHYSIOLOGICAL AND BEHAVIORAL ECOLOGY
Priority areas that should take precedence
within this research area
While it is difficult to foresee the variety of ways polar
bears in zoos could help to better understand the
behavioral and physiological ecology of polar bears,
some recent themes have emerged as important
contributions that could be made in the coming years.
1. Improve and validate methods for monitoring
exposure to stressors and the state of chronic
stress via cortisol in hair and urine or other metrics
from blood.
2. Identify the seasonal timing of hair growth and
rates of growth and the factors that affect these
metrics, such as food intake, nutritional condition,
size, age, sex, and environmental conditions in
order to improve use of hair as an ecological
monitoring tool for wild polar bears.
3. Continue to improve estimation of energetic costs
in polar bears including identifying the primary
factors affecting these costs, such as sex, age, and
environmental conditions. These efforts should
include quantification of the energetic costs of
reproduction, lactation, and growth.
Columbus Zoo bear sniffing meat in feeding trial.
4. Develop a detailed understanding of social Photo by Devon Sabo.
communication in polar bears and determine how
rapid environmental change may compromise
mate search, courtship, social spacing and 7. Describe the range of maternal care behaviors that
maternal care. are correlated with successful cub rearing.
5. Identifying stimuli to both attract and deter Work currently proposed, underway or
polar bears. Attractants would be invaluable not yet published
for improving capture rates for hair sampling
devices. Studies of deterrents may be invaluable Several studies are currently underway, including
for improving co-existence for human activities in a study of hair growth rates, a comparison of
polar bear habitat. micronutrients in polar bear serum between wild
and zoo bears, an evaluation of optimal dietary
6. Better understand macro and micronutrient macronutrient ratios, estimation of stable isotope
requirements, including relationships between discrimination in the lipid and protein components
intake and weight gain, in order to better of blood serum, and a study of bear behavior for
understand implications of changing diets. improving hair collection.
18 | PRBC Masterplan 2022REPRODUCTION
Reproduction
Advisor: Dr. Erin Curry, CREW, Cincinnati
Zoo & Botanical Garden
Experts: Dr. Laura Graham,
Ryerson University
Dr. Gaby Mastromonaco,
Toronto Zoo
Dr. Justine O’Brien, Taronga
Conservation Society Australia
Dr. Terri Roth, CREW, Cincinnati
Zoo & Botanical Garden
Explanation of the research focus area in
relation to polar bear conservation
Photo © Daniel J. Cox/NaturalExposures.com
A reduction in the availability of Arctic sea ice upon
which polar bears hunt is resulting in decreased female samples can be collected regularly from the ex situ
body weights (Stirling et al. 1999; Rode et al. 2010; population, the concentrations and fluctuations
Obbard et al. 2016), is predicted to result in increased of specific hormones and biomarkers can be
reproductive intervals (Derocher and Stirling, 1994), characterized in controlled settings and throughout
and to negatively impact litter sizes (Molnar et al. the lifetime of an individual, an impossible endeavor
2011). Reproductive success is essential to species when considering the wild population. Information
survival, and reduced fecundity is often a precursor gained from studying zoo bears may allow for more
to a population’s decline. Given the impending crisis accurate assessments of the reproductive physiology
facing wild bears, the advancement of reproductive of wild populations and may provide insights into
monitoring techniques will provide enhanced how variables such as body condition, environmental
methodologies necessary to better determine how the contaminants, and human disturbances may impact
species is coping with the changing environment. reproductive processes of in situ populations.
Anthropogenic impact, such as human-induced Examples of work that has happened in zoo
climate change and environmental contaminants, settings and how it has complemented or
may impact fertility of polar bears, but the ability to
assess the intricacies of reproduction in this species is
informed our understanding of polar bear
hindered by a lack of monitoring methods. In females, biology and management
there is no established technique for diagnosing A growing number of reports have stemmed from
pregnancy or distinguishing true pregnancy research of the ex situ population and have provided
from pseudo-pregnancy; therefore, frequency of insight into the medley of reproductive phenomena
pregnancy loss cannot be determined. In males, experienced by this species:
there are challenges associated with the collection
of semen, so knowledge of baseline gamete biology Non-invasive monitoring methods to better
is deficient. The zoo managed population of polar characterize reproductive processes
bears provides valuable opportunities to develop Fecal and urine progesterone and testosterone
improved monitoring approaches that may enhance metabolite analyses have yielded understanding
our understanding of how various factors impact of ovarian activity, including timing of ovulation
the reproductive physiology of wild bears. Because and re-activation of the corpus luteum in females
PRBC Masterplan 2022 | 19REPRODUCTION
An ultrasound examination is conducted on an anesthetized female polar bear. Photo by Seneca Park Zoo.
that have bred. Progestogen analysis of females on which he was trained, but he failed to generalize to
which were housed without males or with non- novel pregnancies. Fecal testosterone analysis showed
intact males has provided verification that true that testosterone concentrations are significantly
pseudopregnancy does exist in this species (Stoops higher during the breeding season and that males
et al., 2012, Steinman et al., 2017, Knott et al., 2017) housed with females exhibit higher testosterone
and indicates that progesterone concentrations alone than those housed without females, indicating that
cannot be used to infer pregnancy status. Seasonal testosterone concentrations may be influenced by the
and reproductive impact on fecal glucocorticoid (FGC) presence of sexually mature females (Curry et al., 2012).
excretion was studied in a small group of pregnant
and pseudopregnant bears (Bryant and Roth, 2018).
Defining breeding season and assessing
Glucocorticoid patterns varied among individuals
reproductive behaviors
and were not consistent within pregnancy status
An investigation of multi-institutional records has
or across seasons. Fecal protein analyses indicated
that the concentrations of specific proteins and defined the polar bear breeding and cubbing seasons:
protein fragments may be significantly higher in 85% of matings occurs between 12 February and 8 April
pregnant versus pseudo-pregnant females (Curry et (Curry et al., 2012) and 74% of litters were born between
al., 2012); however, additional research is needed to 13 November and 15 December, with mean and median
determine if fecal proteins may provide an accurate, litter birth dates of 29 November (Curry et al., 2015).
reliable pregnancy test. Similarly, in a study aimed to Because entire mating bouts are difficult to observe, and
determine if odor detection dogs could distinguish the precise day of parturition is unknown in wild bears,
fecal samples originating from pregnant versus non- detailed descriptions of breeding and parturition dates
pregnant polar bears (Curry et al., 2021), the dog in zoos may be useful in characterizing the reproductive
alerted on novel samples collected from pregnancies seasonality of this species.
20 | PRBC Masterplan 2022REPRODUCTION
Semen collection and cryopreservation
Performing urethral catheterization in males
anesthetized with medetomidine results in a sperm
recovery rate of 87% in the breeding season and 30%
in the non-breeding season (Wojtusik (in prep), Curry
2016 and 2017). These methods are field-friendly and
potentially could be used to assess sperm parameters
of wild bears while also providing valuable genetic
material for long-term storage. The effects of various
semen extenders and sperm cryopreservation
methods are being studied, and a polar bear sperm
bank has been established. Current cryopreservation
methodologies result in a post-thaw sperm motility
rate of up to 60% (unpublished; CREW).
Priority areas that should take precedence
within this research pillar
The reproduction research priorities are focused on
three strategies which are in alignment with the Polar
Bear Research Council’s mission: 1) Use the ex situ
population to better characterize basic reproductive
physiology and improve monitoring techniques for
comparison and application to in situ polar bears; 2)
conduct research that is necessary for maintaining
a viable, sustainable ex situ population for scientific
research with application to wild bears; and 3) preserve
the extant gene pool to prevent loss of genetic diversity Polar bear sperm. Photo by Cincinnati Zoo & Botanical
that could occur due to environmental changes. Garden.
1. Improve and expand reproductive monitoring behaviors. Identifying factors or management
capabilities: Although fecal steroid metabolite strategies among individuals and institutions
analysis provides insight into reproductive that experience reproductive success may allow
processes, no definitive diagnostic indicators predictions to be made on potential causes of
of ovarian activity and pregnancy have been reproductive failure in wild bears. Maintaining a
validated. Efforts should be made to further viable ex situ population is essential in serving
investigate non-invasive (feces, urine, saliva, other) a wide range of conservation-relevant research
and minimally invasive (serum) biological matrices needs, but currently, the ex situ population is
and novel approaches to expand and improve not self-sustaining due to low reproductive
the ability to monitor reproductive processes. success in recent years. Research needs include:
Specific areas that warrant research are: methods understanding optimal body condition and
to diagnose and monitor pregnancy, including nutritional needs for cub production; determining
points of pregnancy failure; characterization of the influence of environmental contaminants on
ovarian dynamics, including the stimulus required reproductive processes; identifying exogenous
for ovulation; evaluation of steroid hormones
and/or endogenous cues for regulation of
and biosynthesis pathways; investigation of
emergence from embryonic diapause; evaluating
temporal trends in non-steroid hormones, and;
housing and/or management strategies, including
examination of biomarkers of metabolism and
their relationships to reproduction. light and noise pollution, on reproductive behavior
and cub production; evaluating the genetic
2. Identify factors impacting reproductive relatedness of individuals in zoos, and; developing
success: It is generally unknown why some zoo and utilizing assisted reproductive technologies
managed bears produce cubs and others do not, (ART) to maintain a research population and to
despite exhibiting seemingly normal copulatory preserve valuable genetics.
PRBC Masterplan 2022 | 21REPRODUCTION
3. Assess reproductive anatomy and gamete
biology: There is limited data on the basic
anatomy of polar bear reproductive systems
and pathologies that may impact reproductive
processes. Immobilizations and necropsies provide
opportunities to visualize and evaluate reproductive
tracts, assess pathologies, collect and cryopreserve
gametes to preserve valuable genetic material, and
preserve tissues collected post-mortem.
Reproductive studies currently underway
or not yet published
Non-invasive monitoring: Fecal steroid metabolite
changes associated with sexual maturation (CREW,
manuscript in prep); Dehydroepiandrosterone (DHEAS)
quantification in feces collected from both zoo
and wild bears (Brandhuber, U of Alaska Fairbanks;
quantification of testosterone concentrations in group-
housed vs. solo housed male polar bears (McCart, York
University); PGFM quantification in parturient vs. non-
parturient bears (CREW).
Pregnancy diagnosis: Investigation into specific fecal
proteins as biomarkers of pregnancy using sequential
window acquisition of all theoretical ion fragments
(SWATH; CREW); fecal volatile organic compound (VOC)
analysis (collaboration between CREW and Dr. Wilson
at University of Saskatchewan); fecal metabolomics
profiling (collaboration between CREW and Cincinnati
Children’s Hospital Medical Center) Researchers perform a fertility exam and artificial
insemination procedure. Vaginal endoscopy allows
Serum hormone analysis: Quantification of Anti-Mullerian visualization of the cervix. Photo by Henry Vilas Zoo.
hormone (AMH) concentrations by sex, season, age, and
fertility status (Tompros/CREW); development of a multi-
plex serum panel to measure leptin, prolactin, FSH, LH,
extenders (CREW, Toronto Zoo); laparoscopy and
kisspeptin, melatonin, and Vitamin D in serum banked
from zoo bears (Wojtusik/CREW). ultrasonography of the female polar bear (Justine
O’Brien, SeaWorld & Busch Gardens Reproductive
Identifying factors impacting reproduction: Long-term Research Center (SWBGRRC), Todd Robeck (SWBGRRC),
effects of contraception on reproduction in polar bears and Dean Hendrickson (Colorado State); vaginal
(CREW, manuscript under review); nutrition and body endoscopy, endocrine data (paired fecal and urine),
weight during pregnancy (Toronto Zoo, in process). and AI (Justine O’Brien, Karen Steinman (SWBGRRC),
Physiological assessments of reproductive systems: and CREW); histopathology of reproductive tracts
Semen collection and cryopreservation, both at collected post-mortem (Agnew & Shellabarger);
physical examinations and post-mortem/post- assessment of prevalence of perivulvar dermatitis in
castration (CREW, Toronto Zoo); evaluation of semen zoo bears (Shellabarger).
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